Field of the Invention
The present invention relates to a lubricating apparatus for rotating shaft, and in particular, a lubricating apparatus for supplying oil to a plurality of rotating shafts arranged in a case.
Description of the Related Art
The lubricating apparatus is mounted in, for example, a gear transmission to lubricate bearings of the rotating shafts, engaged portions of gears, and fitted portions of the gears and the rotating shafts. Examples of a method of supplying oil include a method of pumping lubricating oil compressed in an oil pump to each portion to be lubricated via passages inner of rotating shafts and a case wall, a method of scraping oil accumulated on a bottom of a case with gears and supplying the oil to each portion to be lubricated (for example, US2015-0060207 A1, US2015-0308559 A1), and an oil mist lubrication method of lubricating each portion to be lubricated with oil mist filled in a case.
In terms of size of the above-mentioned gear transmission, the transmission can be made compact in the horizontal direction orthogonal to the rotating shafts by adjusting layout of the rotating shafts, especially, the height of the rotating shafts. However, when the rotating shafts is located high, the amount of supplied lubricating oil decreases. In addition, high-load and high-speed rotation of the transmission require an increase in the amount of supplied lubricating oil. According to the forced oil supply method using the oil pump, such decrease in the amount of supplied lubricating oil can be addressed by increasing the capacity of the pump. However, since the oil pump is required, the number of parts increases.